Process of distilling oil shales and the like



Nov. 16,1926. 1,607,240

D. J. L. DAVIS ET AL PROCESS OF DISTILLING OIL SHALES AND THE LIKE 2Sheets-Sheet. l

. gwua'nfoz i ,2. .j L Davv`$, Geo. M14/aduce,

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Nov. 16 1926. 1,607,240

. D. J. DAvls ET AL PROCESS OF DISTILLING OIL SHALES AND THE LIKEl 2Sheets-Sheet 2 Filed Sept'. 20. 1922 Pavs, Geo. W Wallace,

@Hotncq Patented Nov.` 16, 1926.,A

UNITED STATES PATENT OFFICE.

DAVID J'. Il.- DAVIS AND GEORGE W. WALLACE, OE NEW YORx, N. Y.,AssIGNORs To s; E Co1rI1ANY,orI sAN FRANCISCO, CALIFORNIA, A CORPORATIONOE DELAWARE PRoCEss OF DISTILLING OIL sHALEs AND THE LIKE.

Application led September 20, 1922. Serial No. 589,52.

Our invention relates to therecovery of oils .and` by-products fromoil-shales, in which term we include all natural oil-bear-l ingminerals, and consists, morespecifically stated, in a continuous processof obtaining oils, nitrogenous compounds and other byproducts, from'oil-shales aond 'other solid earthy materials, containing hydrocarbonsand which yield oil when subjected to either destructive distillation orsimply to heat.

. ,Heretofore this operation has usually been an intermittent oneperformed in a closed chamber or retort heated externally.

In the process according to our invention, in. contradistinction to theprevious practice, internal heat is utilized forythe distillation, as bythe direct combustion of a portion of the combustible substances presentinthe material being treated, which is constantly fed 4into the lowerend ofthe chamber and upwardly through the same. It is not'material tothe present invention in what manner or`by what meansthe zone of heat is`initiated and maintained, y(this step of the process being in itselfold and disclosed, for example, in the patent to Dundas and Howes, No.1,469,628, issued Oct. 2, 1923 tol Athe assignee of thepresentapplication,)

since the essential features of our invention are the maintenance, inoany way, of la stationaryfzone of heat at or near the top of adistilling chamber, and the continuous upward feed of the material beingtreated into and through said zone.

In the practice of our invention, We pro-.-

pose to proceed as follows: 4

A closed chamber is filled with the shale or similar material to betreated, a zone of I heat is initiated on the top of this charge,

air for combustion is passed downwardly through the charge, which isconstantly renewe byl fresh raw material being fed progressivelyupwardly through the' chamber by means of a mechanical stoker, screwconveyor, o1N other suitable power apparatus. As soon as the fire iskindled on top of the charge, combustion' begins to take place 'intheshale itself and proceeds downwardly until a zone of combustion isformed, which shortly assumes a certain thickness and a certain distancefrom the top ofthe material in the-chamber, both thickness and distancebeing controllable at will by regulating or modifying the air and byvarying vthe rate of feed of the material. The heat, generated in thesaid zoneof combustion and drawn downwardly through the material by thecurrent'of air, sets up destructive distillation reactions .in theupcoming material, which result in the formation of oil, leaving in theresidue, from which all of the volatile hydrocarbons have been removed,a certain amount Of'fxed carbon. 'This residue, containing fixed carbon,is continuously being advanced upwardly intoV the zone of combustion,where-it isburned, land normally supplies enough heat to the 'incomingmaterial to bring about the required `decomposition reactions therein,resulting in the formation of the desired oils. It is evident that,where enough free carbon does not ex- .ist to furnish the requiredamount of heat,

aportion of the hydrocarbon material itself will be burned.

In the case of materials carrying free oil, the heat, carried downwardlythrough the material'from the zone of combustion by the content of thelgaseous Aproducts of combustion,'will vola- ,tilize the contained oil.In the majority of materials, however, destructive. distillation -occursand the resulting Oil is a decomposition product of the complex solidhydrocarbons existing in the material, Means are provided for theremoval of the residue from the top of the charge as fast as it is fedup.

Y In practicing our process, it is essential to be able to .control thetemperature, location and extent of the zone of combustion, so as tovary the intensity and quantity of the heat transmitted to the rawmaterial being lfed up towards said zone, thereby preventing theformation of objectionable clinkers and the. destruction of thehydrocarbon oils initially formed.A This control is obtained by varyingthe rate of upward feed of the material and bydiminishing the percentage-of' oxygen in the mediumof-.combustiom either by returninga percentageof the gaseous products of combustion, which leave the cham'- ber, tothe incomingair, or by admitting a lolo percentage of water vapor orother inert gas l Where the shale, or. material being treated, containsa sufficient amount of nltrogenous matter, steam lis theA preferredmedium of control as, when steam is used, an increased.l uantity ofammonlum compounds -wlll be ormed. 4TheI degree to which' the-'air used,with the air"l used to support combustion.

treated; in many cases no modification is required.

There are many advantages accruing from the use of our process whichwilly now be evident to one skilled'in the art. In addition to the lowinitial and operating cost of the apparatus used to practice theprocess,

"therefrom, which assists in elevating the material to its decompositiontemperature, as it approaches the zoneof combustion.

In the accompanying two sheets of drawing, we have illustrated, by wayof example, one form of apparatus by which our process can be carriedout commercially, although 'we lwish it to'be distinctly understood thatwe are in no way limited to the precise form of apparatus shown and thatthe process is capable of being performed in other apparatus. Forinstance, the chamber may be inclined instead of vertical, asrepresented in the drawings, in which,

Fig. 1 is a side elevation of the apparatus, a portion of the chamberwall being broken away.

Fig. 2 1s a plaii sectional view of the same l 1ty necessary, todescribe here the apparatus,

i on line 2-2 of Fig. 3, and

Fig. 3 is a vertical central section through the upper part of thechamber.

In the example illustrated in these views, the closedchamber 1, in whichthe material lis treated, issupported ina vertical position, by columns2, and consists of a cylindrical section 3 at the top, a conical section4 below said cylindrical section, and a curved tapering section .15`leading into the bottom of said conical section, the other -end of'saidcurved section having its axis horizontal and constituting the feedinlet for the raw material. The top of section 3 is surrounded by atrough 46 and the chamber is closed by a cover 7. A down-spout .8 forthe spent material leads awayjfrom anopening in the bottom of saidtrough. On a central shaft10, drivenby the bevel gear drive 11, -arecarried the scraper arms 12, on the ends ofwhich are blades 13,traveling in theA trough 6. From the horizontal end of section 5, asuitably trapped outlet pipe 14 for the oils leads downward, and to theface of said end is securedthe feed casing 15, containing a reciprocatorpiston 16, or other suitable means for fee ing the material .upwardlythrough the chamber 1.

The axis ofthe casing 15 is somewhatabove that of the horizontal end ofsection 5, so that the incoming material will not interfere with theescape of t'he oils through the outlet pipe 14. The raw material issupplied to the casing 15, for example, from a closed bin 18. An inlet19 is provided through the cover 7 for the air and other gases and asuction blower may be connected to the outlet 21 below the bin 18 tocreate a partial vacuum in the apparatus to draw the air, etc, downwardthroughthe material, or the air may be forced into the chamberand thepressure in the same be maintained above atmospheric, if desired,instead of using suction and a pressure below atmospheric. The vapors,which are not condensed by their passage through the raw material in thechamber, are preferably drawn off through said outlet 21, but may bedrawn off through the pipe 20,

4through which the bin 18 is filled, so as to which forms thesubject-matter of application Serial No. 589,353, led ofeven dateherewith, in detail,l since it is desireditos merely illustrate onemeans which may be employed to carry out the process, the operation ofwhich will be readily understood `A fromk the above description.. As fbefore stated, the reactions which take place in the operation of ourprocess are in no way different as far as we are aware, from those whichtake place in the Dundas and Howes process of Patent No. 1,469,628,aforesaid, and the regulation and modification of the air and the rateof upward feed of the material are controlled as the conditionsobtaining, and results desired, at any given time, required.

Having thus described our invention', what we claim is' I 1. Theroce'ssv of distilling oil shale, which consists in feeding a' column ofshale upwardly through a closed chamber, creating a zone of combustionin the shale at the top of said chamber, passing air downwardly intosaid zone to maintain it and toproduce a zone of distillationimmediately below said zone of combustion, and

continuously removing the spent shale from the top of said chamben 2.The process of dstilling oil shale, which consists in progressivelyfeeding a column of shale upwardly through a closed chamber, creating azone of combustion in' the shale at the top of said chamber, passing airdownwardly into said zone to maintain it and to produce a zone ofdistillation l0 immediately beneath it, continuously removing thedistilled oils andwapors 4from the 4 bottom of the chamber and the spentshale from the top thereof, and modifying the oxidizing el'ects of theair introduced by adding products of combustion thereto.

In testimony whereof We have hereunto set our hands.

DAVID J. L. DAVIS. GEORGE W. WALLACE.

